package com.ihr360.job.core.item;

/**
 * <p>
 * Marker interface defining a contract for periodically storing state and restoring from that state should an error
 * occur.
 * <p>
 *
 * @author Dave Syer
 * @author Lucas Ward
 *
 */
public interface ItemStream {

    /**
     * Open the stream for the provided {@link ExecutionContext}.
     *
     * @param executionContext current step's {@link org.springframework.batch.item.ExecutionContext}.  Will be the
     *                            executionContext from the last run of the step on a restart.
     * @throws IllegalArgumentException if context is null
     */
    void open(ExecutionContext executionContext) throws ItemStreamException;

    /**
     * Indicates that the execution context provided during open is about to be saved. If any state is remaining, but
     * has not been put in the context, it should be added here.
     *
     * @param executionContext to be updated
     * @throws IllegalArgumentException if executionContext is null.
     */
    void update(ExecutionContext executionContext) throws ItemStreamException;

    /**
     * If any resources are needed for the stream to operate they need to be destroyed here. Once this method has been
     * called all other methods (except open) may throw an exception.
     */
    void close() throws ItemStreamException;
}